This invention is concerned with selective .alpha..sub.2 -adrenoceptor antagonists which are of value as modifiers of gastro-intestinal motility in the treatment of colonic spasm, irritable bowel syndrome and constipation.
.alpha..sub.2 -Adrenergic receptor antagonism is generally associated with antidepressant, antidiabetic, antihypertensive, antiobesity and platelet aggregation inhibition activity. These compounds have now been found to modify gastrointestinal motility and are useful in the treatment of colonic spasm, irritable bowel syndrome and constipation.